bcache: Make sure blocksize isn't smaller than device blocksize
Sanity check to make sure we don't end up doing IO the device doesn't
support.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 6817ea4..b360147 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -139,13 +139,17 @@
if (bch_is_zero(sb->uuid, 16))
goto err;
+ sb->block_size = le16_to_cpu(s->block_size);
+
+ err = "Superblock block size smaller than device block size";
+ if (sb->block_size << 9 < bdev_logical_block_size(bdev))
+ goto err;
+
switch (sb->version) {
case BCACHE_SB_VERSION_BDEV:
- sb->block_size = le16_to_cpu(s->block_size);
sb->data_offset = BDEV_DATA_START_DEFAULT;
break;
case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
- sb->block_size = le16_to_cpu(s->block_size);
sb->data_offset = le64_to_cpu(s->data_offset);
err = "Bad data offset";